HomeMy WebLinkAboutStormwater Pollution Plan - PLN General - 5/30/2012 Mason County
Construction Stormwater Pollution Plan Submittal Checklist
Project Name: BELFAIR LOG PLAZA
Parcel#'s: 12329-44-00010
County Project No.:
Author of Report: MICHAEL F. WNEK, P.E.
Minimum Requirements of the DOE 2005 Stormwater Manual
The Stormwater checklist identifies the minimum requirements of the DOE 2005 Stormwater Manual.
The Checklist is intended to identify the locations within the plan that addresses the minimum
requirements. Mason County will not perform a technical evaluation of the submittal. Rather,the
checklist provides a guide to allow Mason County to review the submittal and determine if the applicant
has addressed the minimum features that make up a Stormwater plan.
It is incumbent upon the applicant and his/her engineer to fulfill all the applicable requirements of the
2005 Stormwater Plan as it relates to the proposed project. Review by Mason County is intended to
determine if the plan has addressed the minimum requirements. Applicant's engineer shall be responsible
for the technical accuracy of the submitted Stormwater plan.
During construction of the project,the stormwater plan engineer of record or his/her authorized
representative shall inspect the site to ensure the stormwater plan is being implemented as designed. Upon
completion of the project,the engineer or his authorized representative shall be required to certify that the
stormwater plan has been implemented as designed.
Failure to meet the minimum requirements could result in delay or rejection of the application until the
deficiencies are corrected.
Section I—Construction SWPPP Narrative
1. Construction Stormwater Pollution Prevention Elements
X a. Describe how each of the Construction Stormwater Pollution Prevention Element has been
addressed though the Construction SWPPP. (SHEET:) C1
X b. Identify the type and location of BMPs used to satisfy the required element. C 1
mac. Written justification identifying the reason an element is not applicable to the proposal.
12 Required Elements—Construction Stormwater Pollution Prevention Plan
X
1. Mark Clearing Limits, See page/paragraph Cl, ESC #2
X 2. Establish Construction Access, See page/paragraph C1, ESC#10
X 3. Control Flow Rates, See page/paragraph Cl, ESC #6
X 4. Install Sediment Controls, See page/paragraph C1, ESC #4
X 5. Stabilize Soils, See page/paragraph Cl, ESC#1
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X 6. Protect Slopes, See page/paragraph Cl, ESC #5
_2L_7. Protect Drain Inlets, See page/paragraph C1, ESC#8
X 8. Stabilize Channels and Outlets, See page/paragraph C1, ESC#7
X 9. Control Pollutants, See page/paragraph Cl, ESC #13
X 10. Control De- Watering, See page/paragraph Cl, ESC #9, #12
X 11. Maintain BMPs, See page/paragraph Cl, ESC#11, #14
X 12. Manage the Project, See page/paragraph Cl, ESC#3, #15
2. Project Description
X a. Total project area. Acres 1.0 Sq. Ft.
X b. Total proposed impervious area. Acres Sq. Ft. 7,200
X c. Total proposed are to be disturbed, included off-site borrow and fill areas.
Acres 0.24 Sq. Ft.
X d. Total volumes of proposed cut and fill. Cubic Yards 300 cy
3. Existing Site Conditions
X a. Description of the existing topography. See page/paragraph D.A. (DRAINAGE ANALYSIS)2.a.
X b. Description of the existing vegetation. See page/paragraph D.A. 2.b.
X c. Description of the existing drainage. See page/paragraph D.A. 2J.
4. Adjacent Areas
X I. Description of adjacent areas that may be affected by the site disturbance
X a. Streams, See page/paragraph D.A. 2.f.
X b. Lakes, See page/paragraph D.A. 21
X c. Wetlands, See page/paragraph D.A. 2.f.
X d. Residential Areas, See page/paragraph D.A. 2.d.
X e. Roads, See page/paragraph D.A. 2.d.
N/Af. Other, See page/paragraph
X II. Description of the downstream drainage path leading from the site to the receiving body of water.
(Minimum distance of 400 yards), See page/paragraph D.A. 7.a. to 7.d.
5. Critical Areas
N/Aa. Description of critical areas that are on or adjacent to the site.
See page/paragraph
WAb. Description of special requirements for working in or near critical areas.
See page/paragraph
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6. Soils
Description of on-site soils.
X a. Soil name(s), See page/paragraph D.A. 2.h.
X b. Soil mapping unit, See page/paragraph D.A. 21.
X c. Erodibility, See page/paragraph D.A. 12.
X d. Settleability, See page/paragraph D.A. 12.
X e. Permeability, See page/paragraph D.A. 1 I.e.
X f. Depth, See page/paragraph D.A. 1 l.c.
X g. Texture, See page/paragraph D.A. 1 l.c.
X
h. Soil Structure, See page/paragraph D.A. 11.c.
7. Erosion Problem Areas
X Description of potential erosion problems on site. See page/paragraph D.A. 12.
8. Construction Phasing
X a. Construction sequence, See page/paragraph C 1
X b. Construction phasing(if proposed) , See page/paragraph Cl
9. Construction Schedule
X I. Provide a proposed construction schedule, See page/paragraph C 1
II. Wet Season Construction Activities
X a. Proposed wet season construction activities, See page/paragraph C 1
N/Ab. Proposed wet season construction restraints for environmentally sensitive/critical areas. See
page/paragraph
10. Engineering Calculations
Provide Design Calculations.
N/A a. Sediment Ponds/Traps, See page/paragraph
N/A b. Diversions, See page/paragraph
NLA c. Waterways, See page/paragraph
X d. Runoff/Stormwater Detention Calculations, See page/paragraph D.A. 11. & Section E
11. Operations and Maintenance.
An operation and maintenance schedule shall be provided for all proposed stormwater facilities and
BMPs, and the party (or parties)responsible for maintenance and operation shall be identified. An
operation and maintenance (O&M)Declaration of Covenant will be required to cover all privately
owned and maintained stormwater facilities. O&M Declaration of Covenant forms are available at
the Mason County Permit Assistance Center,426 W. Cedar Street, Shelton, WA 98584. The
proponent shall record a copy of the completed Declaration with the Mason County Auditors' office.
A copy of the recorded document must be submitted to the Permit Assistance Center together with
this completed Checklist. See page/paragraph
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Section II—Erosion and Sediment Control Plans
1. General
X a. Vicinity Map, See page/paragraph C1
N/A b. Clearing and Grading Approval Block, See page/paragraph
X c. Erosion and Sediment Control Notes, See page/paragraph C 1
2. Site Plan
X a. Legal description of subject property
x b.North Arrow
N/A. Indicate boundaries of existing vegetations, e.g. tree lines,pasture areas, etc.
N/A d. Identify and label areas of potential erosion problems, See page/paragraph
N/Ae. Identify any on-site or adjacent surface waters, critical areas and associated buffers
N/A f. Identify FEMA base flood boundaries and Shoreline Management boundaries (if applicable), See
page/paragraph
X g. Show existing and proposed contours
X h. Indicate drainage basins and direction of flow for individual drainage areas
X i. Label final grade contours and identify developed condition drainage basins
X j. Delineate areas that are to be cleared and graded
X k. Show all cut and fill slopes indicating top and bottom of slope catch lines
3. Conveyance Systems
N/X. Designate locations for swales, interceptor trenches,or ditches
X b. Show all temporary and permanent drainage pipes, ditches, or cut-off trenches required for erosion
and sediment control
X c. Provide minimum slope and cover for all temporary pipes or call out pipe inverts
X d. Show grades, dimensions, and direction of flow in all ditches, swales, culverts, and pipes
N/A e. Provide details for bypassing off-site runoff around disturbed areas
X f. Indicate locations and outlets of any dewatering systems
4. Location of Detention BMPs
N/A a. Identify location of detention BMPs.
5. Erosion and Sediment Control Facilities
N/A a. Show the locations of sediment trap(s),pond(s), and pipe structures.
N/A b. Dimension pond berm widths and inside and outside pond slopes.
N/A c. Indicate the trap/pond storage required and the depth, length, and width dimensions.
X d. Provide typical section views through pond and outlet structure. (POROUS PAVEMENT)
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N/Ae. Provide typical details of gravel cone and standpipe, and/or other filtering devices.
N/A f. Detail stabilization techniques for outlet/inlet.
X g. Detail control/restrictor device location and details.
N/A h. Specify mulch and/or recommended cover of berms and slopes.
N/A i. Provide rock specifications and detail for rock check dams.
N/A j. Specify spacing for rock check dams as required.
N/A k. Provide front and side sections of typical rock check dams.
N/A 1. Indicate the locations and provide details and specifications for silt fabric.
X in. Locate the construction entrance and provide a detail.
6. Detailed Drawings
X a. Any structural practices used that are not referenced in the Ecology Manual should be explained and
illustrated with detailed drawings.
7. Other Pollutant BMPs
X a. Indicate on the site plan the location of BMPs to be used for the control of pollutants other than
sediment, e.g. concrete wash water. Cl - CONCRETE HANDLING
8. Monitoring Locations
N/A a. Indicate on the site plan the water quality sampling locations to be used for monitoring water quality
on the construction site, if applicable.
I certify that the stormwater plan submitted for this project fulfills the applicable provisions of the 2005
DOE Stormwater Manual.
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05-09- )?-
Engin Date
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Applicant Date SIGNAL
Place eng. stamp and sign/date above.
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WNEK ENGINEERING
Consulting Civil Engineer
3388 NW Byron St., Suite 200, Silverdale, WA 98383
360-692-3802 (fax)-692-1051
May 9, 2012
Summary of Stormwater Mitigation Plan
Belfair Log Plaza
Quantity & Quality Controls:
The project will create greater than 5,000 square feet of new impervious area. Therefore
Minimum Requirement (MR) #1 through #10 are required.
However, since there is less than 10,000 sf of new effective impervious area, flow control (MR
#7) is not required. However, see below.
On-Site Stormwater Management (MR #5) will be provided by constructing the parking area with
porous pavement.
Water quality treatment will be provide under the porous pavement by native soils having an
adequate cation exchange capacity CEC>5 and b providingsufficient infiltration area to
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infiltrate flows up to the water-quality design rate.
Flow control will be met for the new pavement area. The porous pavement contains a subdrain
with an outlet riser to meter the discharge. The riser design is balanced to restrict outflows so
that water quality criteria can be met; yet allow some discharge to economize the depth of
storage rock required under the porous pavement.
Erosion & Sedimentation Control:
The project requires a SWPP plan. The project does not require an NPDES permit.
In consideration of the flat terrain, along with the small disturbance area, only basic erosion
control BMP's are necessary.
Discharge Point:
Mitigated runoff is discharged to an existing catch basin, which in-turn discharges to the east
roadside ditch of SR-3.
GACivilEng\553-Belfair Log Plaza\Storm\Report\Stormwater Concept Summary.doc